2XSJ

Structure of desulforubidin from Desulfomicrobium norvegicum

Summary for 2XSJ

• Entry DOI: 10.2210/pdb2xsj/pdb
• Descriptor: SULFITE REDUCTASE ALPHA SUBUNIT, SULFITE REDUCTASE BETA SUBUNIT, SULFUR RELAY PROTEIN, TUSE/DSRC/DSVC FAMILY, ... (7 entities in total)
• Functional Keywords: dissimilatory sulfite reductase, sulfur metabolism, dsrabc, oxidoreductase
• Biological source: DESULFOMICROBIUM NORVEGICUM; More
• Total number of polymer chains: 6
• Total formula weight: 215826.67

Authors

Oliveira, T.F.,Khan, A.R.,Pereira, I.A.C.,Archer, M. (deposition date: 2010-09-29, release date: 2011-08-24, Last modification date: 2024-11-13)

Primary citation

Oliveira, T.F.,Franklin, E.,Afonso, J.P.,Khan, A.R.,Oldham, N.J.,Pereira, I.A.C.,Archer, M.
Structural Insights Into Dissimilatory Sulfite Reductases: Structure of Desulforubidin from Desulfomicrobium Norvegicum
Front.Microbiol., 2:71-, 2011

PubMed Abstract: Dissimilatory sulfite reductases (dSiRs) are crucial enzymes in bacterial sulfur-based energy metabolism, which are likely to have been present in some of the earliest life forms on Earth. Several classes of dSiRs have been proposed on the basis of different biochemical and spectroscopic properties, but it is not clear whether this corresponds to actual physiological or structural differences. Here, we describe the first structure of a dSiR from the desulforubidin class isolated from Desulfomicrobium norvegicum. The desulforubidin (Drub) structure is assembled as α(2)β(2)γ(2), in which two DsrC proteins are bound to the core [DsrA](2)[DsrB](2) unit, as reported for the desulfoviridin (Dvir) structure from Desulfovibrio vulgaris. Unlike Dvir, four sirohemes and eight [4Fe-4S] clusters are present in Drub. However, the structure indicates that only two of the Drub coupled siroheme-[4Fe-4S] cofactors are catalytically active. Mass spectrometry studies of purified Drub and Dvir show that both proteins present different oligomeric complex forms that bind two, one, or no DsrC proteins, providing an explanation for conflicting spectroscopic and biochemical results in the literature, and further indicating that DsrC is not a subunit of dSiR, but rather a protein with which it interacts.

PubMed: 21833321
DOI: 10.3389/FMICB.2011.00071

Experimental method

X-RAY DIFFRACTION (2.5 Å)